Previous studies have shown that a magnetic pulse affected the orientation of passerine migrants for a short period only for about 3 days, the birds' headings were deflected eastward from their migratory direction, followed by a phase of disorientation, with the birds returning to their normal migratory direction after about 10 days. To analyse the processes involved in the fading of hte pulse effect, migratory birds were subjected to a second, identical pulse 16 days after the first pulse, when the effect of that pulse had disappeared. This second pulse affected the birds' behaviour in a different way: it caused an increase in the scatter of the birds' headings for 2 days, after which the birds showed normal migratory oreintation again. These observations are at variance with the hypothesis that the magnettite-based receptor had been fully restored, but als with the hypothesis that the input of this receptor was ignored. They indicate dynamic processes,w hich include changes in the affected receptor, but at the same time cause the birds to weigh and rate the altered input differently. The bearing of these findings on the question of whether single domains or superparamagnetic particles are involved in the magnetite-based receptors is discussed.

Magnetite-based magnetoreception the effect of repeated pulsing on the orientation of migratory birds

en_US

dc.type

Journal Article

utslib.citation.volume

5

en_US

utslib.citation.volume

193

en_US

utslib.for

0602 Ecology

en_US

utslib.for

06 Biological Sciences

en_US

utslib.for

11 Medical and Health Sciences

en_US

pubs.embargo.period

Not known

en_US

pubs.organisational-group

/University of Technology Sydney

pubs.organisational-group

/University of Technology Sydney/Faculty of Science

pubs.organisational-group

/University of Technology Sydney/Faculty of Science/School of Life Sciences

utslib.copyright.status

closed_access

pubs.consider-herdc

true

en_US

pubs.issue

5

en_US

pubs.volume

193

en_US

Abstract:

Previous studies have shown that a magnetic pulse affected the orientation of passerine migrants for a short period only for about 3 days, the birds' headings were deflected eastward from their migratory direction, followed by a phase of disorientation, with the birds returning to their normal migratory direction after about 10 days. To analyse the processes involved in the fading of hte pulse effect, migratory birds were subjected to a second, identical pulse 16 days after the first pulse, when the effect of that pulse had disappeared. This second pulse affected the birds' behaviour in a different way: it caused an increase in the scatter of the birds' headings for 2 days, after which the birds showed normal migratory oreintation again. These observations are at variance with the hypothesis that the magnettite-based receptor had been fully restored, but als with the hypothesis that the input of this receptor was ignored. They indicate dynamic processes,w hich include changes in the affected receptor, but at the same time cause the birds to weigh and rate the altered input differently. The bearing of these findings on the question of whether single domains or superparamagnetic particles are involved in the magnetite-based receptors is discussed.